perf/x86/amd/uncore: Add PerfMonV2 DF event format

If AMD Performance Monitoring Version 2 (PerfMonV2) is
supported, use bits 0-7, 32-37 as EventSelect and bits
8-15, 24-27 as UnitMask for Data Fabric (DF) events.

Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/ffc24d5a3375b1d6e457d88e83241114de5c1942.1652954372.git.sandipan.das@amd.com